Summary: In your project's Sketch Scene, tap the Facets tab in the bottom toolbar, select your pitch value (or other facet labels) in the drawer, and tap on the target facet to apply.
To apply the same pitch value to all facets, select your desired value and tap "Apply to all."
Watch the video below to see the process:
Note: Make sure you input pitch so RoofSnap can account for the slope of the roof and calculate your square count as well as linear feet measurements.